A general display panel comprises only one data driving circuit, which is located at a central position of an upper part of the display panel. In this way, a length from a data line of the data driving circuit to a pixel column located at an edge area is greater than a length from a data line of the data driving circuit to a pixel column located at a central area. However, a wire resistance of the data line per se is relatively large, which would cause that certain difference of luminance exists in the pixel column located at the edge area and the pixel column located at the central area.
As the size of the display panel is increasingly larger, a distance from the data driving circuit to pixel columns located at left and right sides becomes further and further, and the length of the data line of the data driving circuit connected to the pixel column located at the edge area becomes longer and longer. Correspondingly, the resulted differences of luminance among different areas also become larger and larger.